Viral diseases inflict man, plants, insects, and animals. The prevention and control of viral diseases have important health and economic implications.
Viral diseases contribute to inflictions in humans including common colds, herpes and cancer and the importance of their control is obvious. Also important is control of viral diseases in animals for economic reasons as well as the ability of such animals to become virus reservoirs or carriers which facilitate the spreading of viral diseases to humans. Viral plant diseases have been known to have a disruptive effect on the cultivation of fruit trees, tobacco, and various vegetables. Insect viral diseases are also of interest because of the insects' ability to transfer viral diseases to humans.
The prevention and control of viral diseases is thus of prime importance to man and considerable research has been devoted to antiviral measures. Certain methods and chemical compositions have been developed which aid in inhibiting, controlling or destroying viruses but new methods and antiviral chemical compositions are needed.
U.S. Pat. Nos. 4,162,308 and 4,162,309 to Calvin and Ellis describe that water soluble extracts from marine red algae have been found to be effective to inhibit the growth of certain herpes viruses.
U.S. Pat. No. 4,162,308 describes water soluble extracts from marine red algae selected from a group consisting of Turnerella mertensiana, Schizymenia epiphytica, Turnerella pennyi and mixtures thereof as effective to inhibit the growth of herpes simplex virus, type 1 and type 2, and herpes zoster, and to relieve the pain caused by infection attributable to such viruses.
U.S. Pat. No. 4,162,309 describes the use of water soluble extracts from marine red algae selected from a group consisting of Neodilsea americana and Neodilsea integra and mixtures thereof to inhibit the growth of herpes simplex virus, type 1 and type 2, and herpes zoster, and to relieve the pain caused by infection attributable to such viruses. The entire disclosures of U.S. Pat. Nos. 4,162,308 and 4,162,309 are hereby incorporated herein by reference.
Crews et al in "Bio-Active Monoterpenes from Red Seaweeds", Phytochemistry Vol. 23 No. 7 Pp. 1449-1451, Pergamon Press Ltd., Great Britain, 1984, describe the bioactivity of seaweed derived monoterpenes. Crews et al disclose halogenated monoterpenes which are extracted from red algae Chondrococcus hornemanni with methylene chloride. The halogenated monoterpenes were shown to be bioactive in various applications and biotoxic against insects.
In addition to the water soluble red algae extractions described in the above noted U.S. Patent applications to Calvin and Ellis and the halogenated monoterpenes of Crews et al other compounds have been isolated from red algae and marine organisms known as sea hares which are mollusks which diet on red algae. These compounds include halogenated chamigrenes and have been described in various literature references including P. J. Scheuer, Ed. Marine Natural Products Volume 1 (Martin) and Volume 5 (Erickson) Academic Press, 1978; 1983, the entire disclosure of this reference is hereby incorporated herein by reference.
Prevention, control of the growth and regression of tumors in mammals is also of importance to man. Considerable research has been devoted to oncology and antitumor measures. While certain methods and chemical compositions have been developed which aid in inhibiting or controlling tumors new methods and antitumor chemical compositions are need.
It has now been found that certain cyclohexadienone compounds derived from extracts of red algae possess useful antiviral and antitumor activity.